IBE: The growth pattern of Neanderthals reconstructed

News from IBE (CSIC-UPF)

Neanderthals’ growth rate is very similar to that of Homo sapiens, and differences have been observed in the development of the brain and spine of these two human species. These are the main findings of a study published in Science which focusses on a near eight-year-old Neanderthal child who lived in the Asturian cave of El Sidrón. The study is led by Antonio Rosas, researcher of the Spanish National Research Council (CSIC), and among its authors is Carles Lalueza-Fox, the principal investigator of the Paleogenomics Lab of the IBE.

"Discerning the differences and similarities in growth patterns between Neanderthals and modern humans helps us better define our own history. Modern humans and Neanderthals emerged from a common recent ancestor, and this is manifested in a similar overall growth rate", explains Rosas. As fellow CSIC researcher Luis Ríos highlights, "Applying paediatric growth assessment methods, this Neanderthal child is no different to a modern-day child". The pattern of vertebral maturation and brain growth, as well as energy constraints during development, may have marked the anatomical shape of Neanderthals.

Neanderthals had a greater cranial capacity than today's humans. Neanderthal adults had an intracranial volume of 1,520 cubic centimetres, while that of modern adult man is 1,195 cubic centimetres. That of the Neanderthal child in the study had reached 1,330 cubic centimetres at the time of his death, in other words, 87.5% of the total reached at eight years of age. At that age, the development of a modern-day child's cranial capacity has already been fully completed.

"Developing a large brain involves significant energy expenditure and, consequently, this hinders the growth of other parts of the body. In sapiens, the development of the brain during childhood has a high energetic cost and, as a result, the development of the rest of the body slows down," Rosas explains.